摘要
在气体绝缘变电站(gas insulated substation,GIS)的实际运行工况中,开关操作会使GIS设备承受操作冲击过电压,导致盆式绝缘子表面积聚表面电荷,表面电荷的存在不仅会使得局部电场发生畸变,更为沿面放电的发展提供了电荷,是造成绝缘子沿面闪络的重要因素。该文以实际的252k V GIS盆式绝缘子为试验模型,建立了表面电荷测量试验平台,采用静电探头法测量了SF6气体密闭环境下盆式绝缘子的表面电荷,获得了操作冲击电压作用下盆式绝缘子表面电荷积聚特性及其外施电压作用次数和电压幅值对其的影响。研究结果表明:无论在正极性或负极性操作冲击电压下,绝缘子表面均同时积聚正负极性电荷,但是负极性电荷相比于正电荷积聚量更大,且正极性电压下此现象更为明显;正极性操作冲击电压下,随着电压幅值的增加,绝缘子表面电荷平均积聚量明显增加,最高电荷幅值为-0.52μC/m^2,而负极性电压下,电荷平均积聚量表现出先增大后减小的趋势,其电荷平均密度最大为-0.16μC/m^2;表面电荷积聚量随着外施电压次数的增加逐渐增大,正极电压下表面电荷积聚量的增幅明显,而负极性电压下表面电荷增幅较小,但分布较均匀。该文研究所得到的操作冲击电压下GIS表明电荷积聚特性,进一步强调了由表面电荷引起的实际工况下设备绝缘问题的重要性,可为GIS设备绝缘子的优化设计提供参考。
Under the actual operating conditions of Gas Insulated Substation （GIS）, the insulator might withstand switching impulse voltage, leading the charge accumulating on the surface of insulators. The accumulated surface charge can not only distort the distribution of electric field but also provide charge for further discharge along the surface, which is the key factor for the flashover of GIS insulator. Based on an actual 252kV GIS insulator, a set of surface charge measurement system utilizing the static capacitive probe was set up in this paper. According to which, the accumulation characteristic of surface charge under switching pulse voltage and their variation conditions by the influence of amplitude and applied times of voltage were obtained in this paper. The experimental results show that： there are both positive and negative charges accumulating on the surface of insulator, no matter under positive or negative voltage and the amplitude of accumulated negative charge is much larger than that of positive ones, especially under positive voltage; however, the distribution of surface charge under negative voltage showed more uniformity. With the amplitude of applied voltage increasing, the accumulated surface charge had an obvious increase under positive voltage, and the maximum is -0.52μC/m^2, but under negative voltage, the trend of accumulated surface charge is to increase at first then decrease, under which the maximum can reach -0.16μC/m^2. The surface charge increases obviously as the applied time of voltage increases under positive voltage, while there is little increase for the surface charge under negative voltage. The conclusion reached in this paper could provide a further emphasis on importance of the insulating issues caused by the surface charge accumulation and a reference for the optimal design of GIS insulators.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2017年第15期4538-4547,共10页
Proceedings of the CSEE
基金
国家重点基础研究发展计划项目(973项目)(2014CB239502)~~
关键词
气体绝缘金属封闭开关设备
盆式绝缘了
表面电
gas insulated substation （GIS）
basin insulator
surface charge
switching impulse voltage
accumulationcharacteristic
作者简介
齐波（1980），男，博士，副教授，主要研究方向为电气设备绝缘在线监测与故障诊断、空间电场／电荷测量技术、新型介电附料的研制与应用，lqicb@163．com
高春嘉（1991），男，博士研究生，主要研究方向为电气设备绝缘在线监测与故障诊断
邢照亮（1988），男，硕士，工程师，主要研究方向为空间电场／电荷测量技术.
李成榕（1957），男，博士，教授，博士生导师，新世纪百千万人才工程国家级人选，IEEFellow，IEEE的高级会员，主要研究方向为气体放电及脉冲功率技术，电气设备绝缘在线监测与故障诊断。
